libra mailinfo

Extract commit metadata, the commit-message body, and patch text from one plain-text email patch. This is a small, scriptable subset of git mailinfo and uses the same parser as libra am.

Synopsis

libra mailinfo <MSG> <PATCH> < mail

MSG and PATCH are output file paths. The mail is always read from standard input, so this command works outside a Libra repository.

Behavior

The input is limited to 64 MiB and must be UTF-8, single-part text/plain. Supported transfer encodings are 7bit, 8bit, binary, quoted-printable, and base64. From:, Date:, and Subject: are required. Folded headers, UTF-8/US-ASCII RFC 2047 B/Q encoded words, an optional mbox From envelope line, a leading [PATCH ...] subject marker, and the standard in-body From: override are handled.

On success:

• stdout contains Author:, Email:, cleaned Subject:, and Date: lines;
• MSG contains only the decoded message body before the --- separator, with a final newline when the body is non-empty;
• PATCH contains the --- separator, diffstat, diff --git patch, and any trailing signature block.

Both destinations must have existing parent directories, must be distinct after resolving parent-directory aliases, and cannot be - or directories. The complete input and both temporary payloads are validated/written before either destination is replaced. Each final file replacement is atomic, though two separate filesystem paths cannot form one cross-file atomic transaction.

Output control

Option	Meaning
--quiet	Write MSG and PATCH without metadata on stdout.
--json / --machine	Emit the parsed metadata, output paths, and byte counts in the standard JSON envelope. Files are still written.

JSON data contains author, email, subject, date, message_path, patch_path, message_bytes, and patch_bytes.

Exit codes

Code	Meaning
0	The mail was parsed and both output files were replaced.
128	Input, encoding, header, patch split, path, or file I/O validation failed.
129	Required output arguments are missing or invalid.

Examples

libra mailinfo message.txt patch.diff < 0001-fix.patch
libra --quiet mailinfo message.txt patch.diff < 0001-fix.patch
libra --json mailinfo message.txt patch.diff < 0001-fix.patch

Current limitations

The minimal P2-02 surface exposes no Git mailinfo options such as -k, -b, -m, -u, --encoding, --scissors, or --quoted-cr. MIME multipart messages, attachments, non-UTF-8 charsets, multi-message mboxes, binary patches, and patch text without a diff --git section are rejected.